disco 2 coolant problems - help !

air from where? cos if the system was bled properly there's no air left in it...and as the system is under pressure air can't get in it from outside... that 'needle' is not supposed to create a "flow" just to let the expanded coolant back in the tank but keeping it under pressure, it's calibrated to let pass the coolant only at 1.4 bar or more...i stick to what RAVE says no offence, it's just a friendly polemic

sierrafery said:

air from where? cos if the system was bled properly there's no air left in it...and as the system is under pressure air can't get in it from outside... that 'needle' is not supposed to create a "flow" just to let the expanded coolant back in the tank but keeping it under pressure, it's calibrated to let pass the coolant only at 1.4 bar or more...i stick to what RAVE says no offence, it's just a friendly polemic

Click to expand...

No offence at all

I didn't say it was supposed to create any flow at all, it is just a release for air or vapour in the cooling system.

That orifice wouldn't pass diddly squat, even at 8 bar which is what we used to clear it out, it really is a fine jet.

RAVE doesn't tell you that the needle is even there, just the bit about the expanded coolant, which is a bit of nonsense in a closed system running the volumes that are being pumped round when it is hot. That needle plays no part at all in water movement.

Peter

so we can agree that we disagree in that particular case then ...as IMO there's no place for air or steam in a well sealed and properly bled cooling system which keeps the 1.4 bar in it

Yep, a diplomatic solution

Peter

could it be a leaking gasket
that it blows air into the cooling system

still strange that the thermostaat won't open ?

it could be...take it to a sniff test to find out

Have you tried putting the thermostat ball into a pan of boiling water ? Would that work as a test to see if it is opening ?

thermostat is new
but we will try it !
will do a sniff test

but there where no bubbles when running idle with the cap of
(for 20 minutes)

so its quite a riddle !